This invention relates to an electronic portable communications terminal for Internet/network telephony. The invention also relates to a system for Internet/network telephony and to a method for the same.
The invention additionally relates to a computer-readable medium comprising a program which may be caused to execute the method of the invention on one or more computers or CPUs.
Telephony via the Internet (IP telephony) is a very low-cost alternative to ordinary telephony, in particular over long distances. Such systems convert the speech information into and from a suitable digital format, which is divided into data packets that are transported via the Internet itself, the actual transport via the Internet being typically at a fixed price.
Moreover, IP telephony may also be used for communication with a stationary conventional telephone coupled to the existing telephone network, as the Internet may be used for transmitting data to a local gateway which is connected to the existing public switched telephone network (PSTN). Thus, the user need just pay a local telephone charge even for long distance calls, as the Internet is used for the transport of data to the gateway/location concerned.
Such IP telephony systems/solutions will undoubtedly become more attractive as more and more people get access to the Internet and/or are connected in networks, and as the supply of fixed charge, free, permanent and broadband solutions in connection with the Internet and/or other networks gets greater.
Patent publication WO 00/51375 discloses a communication system where a dual-mode device is capable of both cell phone communication and telephone communication on a IP LAN/network. The dual-mode device connects to the LAN/network either via a cable connecting directly to the LAN/network or a cable connecting to a wireless communication device in wireless communication with a wireless LAN/network. The establishment of a connection to the LAN/network is troublesome since a cable is used and restricts the movement of the user when the dual-mode device is being used and requires for special equipment at the connecting point in the case of a wireless LAN/network.
Additionally, the support of both communication formats causes the dual-mode device to be of a complicated and more expensive design with a relative large power usage.
Patent Publication WO 98/57508 relates to a system for wireless communication via a DECT terminal and a base station, such as e.g. a digital wireless telephone connected to a base station. The system uses the IP protocol for passing on digital speech information via the Internet between various base stations (DECT islands), so that a given DECT terminal will receive a call at the base station at which the terminal is present. This provides increased mobility, as the terminal may be used at other base stations.
A gateway (GW) constitutes the very interface to the DECT base station and handles the conversion of telephone numbers into IP addresses, as the DECT terminal itself does not know its PP address which must be unique. Further, the DECT terminal(s) has to be known, identified and/or paired beforehand with the base station in order to establish communication.
Patent Publication WO 99/38311 relates to a system and a corresponding method of providing a wireless RF (Radio Frequency) interface between one or more terminals and an Internet Protocol (IP)/Internet telephone system, so that the terminals may be used for telephony via the Internet. The system uses a base station which partly handles and controls the distribution of information to the various terminals and partly handles the access to the Internet, which means that the base station controls/contains the relevant protocols inter alia in connection with the Internet.
Further, a terminal associated with a given base station cannot readily be used in connection with another base station, as the base station must know the number of terminals in order to allocate to each terminal its unique frequency and/or jump frequency for use in communication, so that the correct information is received/transmitted by the correct terminal.
The two above-mentioned systems both have the drawback that they require a specialized type of equipment (base station, gateway, etc.), which is a great obstacle to the flexibility with respect to mobility and updating/expansion of functionality, since the specialized equipment must be physically present at every single location where the terminals are contemplated for use.